The oxazolidinone antibacterial agents are a novel synthetic class of antimicrobials with potent activity against a number of human and veterinary pathogens, including Gram-positive aerobic bacteria such as multiply-resistant staphylococci and streptococci, anaerobic organisms such as bacteroides and clostridia species, and acid-fast organisms such as Mycobacterium tuberculosis and Mycobacterium avium. 
However, oxazolidinones generally do not demonstrate an activity at a useful level against aerobic Gram-negative organisms. Thus, the use of these oxazolidinone antibacterial agents is limited to infectious states due to Gram-positive bacteria. Accordingly, it is among the objects of the present invention to provide pharmaceutical compounds which have broader antibacterial activity including the activity against aerobic Gram-negative organisms. We have now discovered that the oxazolidinones of the present invention increase the spectrum of activity to include gram-negative organisms such as Haemophilus influenza and Moraxella catarrhalis. 